SSO between a MOSS and a Weblogic web site

The problem

I need to set up single-sign-on between two web sites. The new site is in MOSS 2007. I am migrating to the MOSS-based site from the existing old site that is built in BEA Weblogic with a SUN One web server in front. The MOSS site requires login. The existing site contains applications requiering login (using the Weblogic realm). It is too expensive to migrate the entire site to MOSS at once, so we need to do a migration in several steps having both the old and the new site in production during the overlapping time.

Proposed solution

I am considering IFrameing the existing applications into the new MOSS-based site while migrating them one by one. The problem is that I cannot expect the user first to log on på the MOSS-site and then to logon to the IFramed applications residing on the existing Weblogic site, so we want SSO between them. I am considering using ISA Server (or maybe another Access management product) to achieve this. With ISA Server the both servers need to be in the same domain and use the same Web listener. I think the solution looks good on paper, but the devil is, as always, in the details. I'll write more on this when I have tried this out in reality. If You have any experience on something similar, i'd appreciate any comments on this!

© Copyright 2008, Tomas Elfving